notes: Troubleshooting EIGRP Route Installation

1. EIGRP Is Not Installing Routes—Cause: Auto or Manual Summarization

debugs and verification

show run | section router bgp
show up route x.x.x.x

solution:

The solution to this problem, based on this cause, is more of a design issue. Two places in the network must not send the same summary routes to one another. configure the no auto-summary command.

2.  EIGRP Is Not Installing Routes—Cause: Higher Administrative Distance

deugs and verification

 show ip eigrp topology 150.150.0.0 255.255.0.0

solution:

To fix this problem, you must change the administrative distance of the routing protocols so that external EIGRP routes are preferred. To do so, use the distance command to manipulate the administrative distance of a routing protocol.


   distance 180 192.168.2.2 255.255.255.255

The distance command  sets the RIP administrative distance to 180 for any updates coming from 192.168.2.2. This allows the external EIGRP routes (administrative distance of 170) coming from Router C to be preferred over RIP routes.

3.  EIGRP Is Not Installing Routes—Cause: Duplicate Router IDs

Many times, EIGRP will not install routes because of a duplicate router ID problem. EIGRP does not use router ID as extensively as OSPF. EIGRP uses the notion of router ID only on external routes to prevent loops. EIGRP chooses the router ID based on the highest IP address of the loopback interfaces on the router. If the router doesn't have any loopback interfaces, the highest active IP address of all the interfaces is chosen as the router ID for EIGRP

debugs and verification:

sho run | section router eigrp
debug ip eigrp
show ip eigrp topology 150.150.0.0 255.255.0.0

solution:
The solution to the duplicate router ID problem is to change the IP address of the loopback interface of Router X or to change the IP address of Ethernet 0 in Router A. The rule of thumb: Never configure the same IP address on two places in the network.